Heirs of the the Walmart fortune continue to reduce the family’s holdings of company stock as part of a plan to keep ownership at slightly below the 50% level. Over the summer Robson, Alice and Jim Walton, children of Walmart founders Sam and Helen, sold more than 881,150 shares of Walmart stock in several open market trades from June through August totaling more than $432 million.

The total of the multiple trades in August was around $86 million, adding to more than $346 million from several trades in June, according to filings with the federal Securities and Exchange Commission.

The shares were sold from the Walton Family Holdings Trust leaving this entity with a balance of more than 70.57 million shares as of Aug. 20. The family also owns through the Walton Enterprises LLC another 1.415 billion shares, according to the filings. The three children share equal interests in the Walton Family Holdings Trust. The Walton Enterprises LLC is shared equally by all the three surviving siblings as well as the estate of their brother John Walton, who died in June 2006 in a plane crash.

Walmart has roughly 2.95 billion shares outstanding as of Aug. 20. The two primary family trusts own about 1.485 billion shares or roughly 50.33%.

Each of the Walton children also directly own Walmart stock. Robson, 73, a board member and former Walmart employee owns 3.347 million shares of stock valued at roughly $318 million. He is said to have a net worth of roughly $44.6 billion.

Alice Walton, 68, directly owns 6.748 million shares worth an estimated $641.86 million. She is said to have a net worth of roughly $44.5 billion making her the second wealthiest female billionaire by net worth in the world. She lives in Fort Worth.

Jim Walton, 70, directly owns 10.557 million shares of Walmart stock valued at $1 billion. He has a reported net worth of $44.9 billion. He retired from Walmart’s board in 2016, with his son Steuart approved by shareholders to replace him. Jim Walton runs Arvest Bank, in which the family owns a controlling interest.

Over the past year the Walton Family holdings of Walmart stock increased in value by 18%, or roughly $15 per share, adding more than $22 billion to the net worth of the two trust entities. Directly, the heirs have seen their Walmart share holdings increase by $309 million, collectively.

Every $1 Walmart shares increase in value the Walton Family trust entities grow by roughly $1.5 billion, not including the shares owned outright by the heirs. Jim Walton’s net worth grows by more than $10.5 million for each dollar gain Walmart’s stock price. For Alice Walton the gain is roughly $6.75 million and Rob Walton picks up about $3.4 million.

Shares of Walmart (NYSE: WMT) closed Thursday at $95.19, up 48 cents on the day. For the past 52 weeks the share price has ranged from $77.50 to $109.98. Over the past year the Walmart family share values have swung $17.60 lower and $14.79 higher than Thursday’s close.